1. Field of the Invention
The present invention relates to an infrared ray clinical thermometer for measuring body temperature by detecting an infrared ray radiated from the tympanic membrane.
2. Description of the Related Art
Hitherto, from the sanitary viewpoint, the infrared ray clinical thermometer of this type is usually furnished with a probe cover to protect the probe to be inserted into an external acoustic meatus. That is, since the tip of the probe is opened, and it is hard to clean or sterilize the inside, a cover is used to plug the opening.
Such a probe cover has a membrane for plugging the opening. The infrared ray from the tympanic membrane transmits through the membrane of the probe cover and is detected by the infrared ray detection sensor provided inside the probe.
On the other hand, when measured without using a probe cover, the infrared ray from the tympanic membrane is directly (without transmitting through the membrane) detected by the infrared ray detection sensor.
Therefore, depending on the presence or absence of the fitted probe cover, the intensity of the detected infrared ray varies. To solve this problem, a infrared ray clinical thermometer provided with a mechanism for detecting the presence or absence of a fitted probe cover is known.
An infrared ray clinical thermometer of the prior art having such mechanism for detecting the presence or absence of a fitted probe cover is explained by referring to FIGS. 12 and 13.
FIG. 12 and FIG. 13 are schematic sectional views showing the vicinity of the probe of the infrared ray clinical thermometer of the prior art, and specifically FIG. 12 shows a state prior to fitting the probe cover and FIG. 13 shows a state after fitting the probe cover.
As shown in the diagrams, on the outer circumference of a probe 101 of an infrared ray clinical thermometer 100, an annular recess 101a is provided for receiving a probe cover 105. On the inner circumference of the probe cover 105, an annular bump 105a is provided to be fitted with the recess 101a. Therefore, by the recess-bump engagement, the probe cover 105 is fitted and fixed.
A switch 102 is disposed inside the probe 101. A parting member 103 for making contact with or departing from the switch 102 is also provided. A spring 104 is provided for thrusting this parting member 103 in a direction for detaching the probe cover 105.
The parting member 103 is provided so that its part may project to the outside of the probe 101.
In this configuration, in a state prior to fitting the probe cover 105 as shown in FIG. 12, the parting member 103 is forced by the thrusting force of the spring 104, and the tip of the parting member 103 is apart from the switch 102.
On the other hand, when the probe cover 105 is fitted as shown in FIG. 13, the parting member 103 is pressed, resisting the thrusting force of the spring 104, by the flange provided in the probe cover 105, and its end makes contact with the switch 102.
Thus, as the parting member 103 makes contact with or departs from the switch 102, it is detected by the switch 102, and the presence or absence of the fitted probe cover 105 is detected.
However, such prior art as mentioned above, had the following problems.
In the mechanism for detecting the presence or absence of the fitted probe cover 105, when the probe cover 105 was fitted, the probe cover 105 is forced in a removal direction (detaching direction) by the parting member 103 through the spring 104.
Therefore, if the fitting force of the probe cover 105 (in the illustrated example, fitting force by the recess-bump engagement) is insufficient, the probe cover 105 may be detached.
If the fitting force is increased to solve this problem, a larger force is needed when fitting or detaching the probe cover, and handling is difficult.
Further, a special mechanism may be employed for attaching and detaching the probe cover, such as screw fixing mechanism or special locking mechanism. However, in this case, attaching or detaching may be difficult, the structure may be complicated, or the cost may be increased.
The present invention is devised to solve the problems of the above-mentioned prior art, and it is hence an object thereof to present an infrared ray clinical thermometer with enhanced stability when fitting a probe cover in a simple structure.
To achieve the above mentioned object, the infrared ray clinical thermometer of the present invention comprises a probe to be inserted into an external acoustic meatus, a probe cover fitted to cover the probe, a movable part moving nearly in a direction perpendicular to the detaching direction as the probe cover is detached or attached, and detecting means for detecting the presence or absence of the fitted probe cover by the movement of the movable part.
Herein, the movement of the movable part includes, for example, sliding along a guide, oscillating on an axis, and elastic flexural deformation.
According to the configuration of the present invention, since the movable part is designed to move in a direction nearly perpendicular to the detaching direction of the probe cover, the movable part will not direct a force in the probe cover detaching direction.
Preferably, the movable part has a slope to be pressed to the inner wall of the probe cover by the fitting action of the probe cover to generate a component of force at the inner side of the probe. Thrusting means is provided for thrusting the movable part to the outer side of the probe, when fitting the probe cover, thereby resisting the thrusting force of the thrusting means. The movable part is moved to the inner side of the probe by the component of force generated from the slope. When detaching the probe cover, by the thrusting force of the thrusting means, the movable part is moved to the outer side of the probe.
Alternatively, the movable part has a slope to be pressed to the outer wall of the probe cover by the fitting action of the probe cover to generate a component of force at the outer side of the probe. Thrusting means is provided for thrusting the movable part to the inner side of the probe, when fitting the probe cover, thereby resisting the thrusting force of the thrusting means. The moveable part is moved to the outer side of the probe by the component of force generated from the slope. When detaching the probe cover, by the thrusting force of the thrusting means, the movable part is moved to the inner side of the probe.
Preferably, the detecting means has a switch which makes contact when the movable part moves to the outer side of the probe, and departs when moving to the inner side, or makes contact when the movable part moves to the inner side of the probe, and departs when moving to the outer side.
In another embodiment of the invention, the infrared ray clinical thermometer comprises a probe to be inserted into an external acoustic meatus, a probe cover fitted to cover the entire probe, a holding member provided movably in a direction nearly perpendicular to the detaching direction for holding the probe cover, and detecting means for detecting the presence or absence of the fitted probe cover by the movement of the holding member.
Herein, the movement of the holding member includes, for example, sliding along a guide, oscillating on an axis, and elastic flexural deformation.
According to this embodiment, since the holding member is designed to move in a direction nearly perpendicular to the detaching direction of the probe cover, the movable part will not provide a force in the probe cover detaching direction.
Preferably, the holding member has an engaging portion to be engaged with the probe cover. Thrusting means is further provided to thrust the holding member in a direction so that the engaging portion may be engaged with the probe cover.